


**Feelings in the Heat**

by Xantall_Farwood



Series: Underswap! Papyrus Heat Saga [1]
Category: Undertale (Video Game)
Genre: Alternate Universe - Underswap, F/M, Fluff and Smut, Mating Cycles/In Heat, Nudity, Shameless Smut, Smoking, Swearing
Language: English
Status: Completed
Published: 2016-06-15
Updated: 2016-06-15
Packaged: 2018-07-15 06:31:29
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,634
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7211735
Author URL: https://archiveofourown.org/users/Xantall_Farwood/pseuds/Xantall_Farwood
Summary: <blockquote class="userstuff">
              <p>When Sans calls you in a panic that something is wrong with Papyrus. You of course go to fix it. Papyrus is a jerk but you can't let Sans continue to freak out.</p>
            </blockquote>





	**Feelings in the Heat**

You scratched at the back of your neck staring at the undecorated door. Sans had been in an outright panic when he called you and couldn’t fully explain what was going on. So for the sake of your ears and sanity you went straight to the skeleton brothers’ home. Only to be yanked inside and dragged up the stairs to Papyrus’ room; well door where you currently stood still confused as hell.

“Sans, bud, what is going on?” You ask a little rough to the small skeleton that is still holding your hand. Turning his big blue eyes up you flinch back at the sight of tears. “Hey come on; no need for that.” You said quickly dropping to your knees hugging the little blueberry close.

“Pap won’t come out.” He finally mumbled into your shoulder.

“Well you know the jerk does that sometimes.” You answer quietly before you feel him shaking his head.

“It’s not like normal. He won’t even talk to me.” Sans pulled back looking up at you as his hands clutched at your jacket. “He normally says he’s fine but…but…” With each stutter more tear built. “…But he wouldn’t say anything.” And then tears spilled over. “I don’t understand. Why is he doing this?”

“Oh Sans.” You grumbled as he latched onto your sweater. Looking over the door you begin to form a plan. You could just break into Papyrus’s room but that would upset Sans more. Maybe if… “Hey bud how about you go over to Alphys and Undyne’s place.”

“Why?” He asked sniffing.

“Well I’m going to talk to Papyrus and you know how we get.” He seemed to think about it for a moment then nodded. “And I’m sure you haven’t been to training yet with all this worrying over your brother.”

Sans pulled away. “You are right I haven’t!” He started down the stairs but stopped looking back up with worried blues looking almost like building tears.. “Are…are you sure you can get him out?”

You flash a cocky smile. “Have I ever let you down Sans?”

He shook his head no and headed out the door. Leaning against the wall near the window on the second floor you watched as the little muffin crossed the street and went in to the couple’s home. There was a moment or two before Alphys poked her head out looking around. Opening the window you leaned out and waved. She pointed behind her with a questioning shrug. You returned it with a point behind you and a stone faced glare. There was a second she seemed confused before a wide grin split across her yellow snout and it was followed by a hardy laugh. Giving you an okay sign she stuck her index finger into the ‘O’ it a couple of times. You flipped her off and pulled yourself back in heading towards Papyrus’s room. Stopping outside his door you raised a fist and three solid knocks later it was silent.

“Yo Papyrus open the damn door!” Pressing your ear to the door you heard movement. “I know you’re in there!” There was some kind of mumbling. “Hey asshat I can’t hear you when you bitch behind a foot thick door.” You could clearly make out his bitching tone but something sounded and felt wrong. There was shuffling like someone was moving closer. Carefully you sat down outside the door your back pressed against it. You flipped the hem of your dress playing with it. You had been on a blind date when Sans had called.

The guy had been hot too and he was total digging you or at you thought by the intense way he had kissed you and then went after your neck. It hadn’t been five minutes after you sat down next to him that he had his hand under your skirt and fingers rubbing you through the fabric of your panties. Damn you had been expecting to get some tonight just to get over your dry spell but Papyrus had to pull this shit.

“You’re scaring Sans.” You hadn’t heard him approach the door but like always you felt him closer than before. The connection you and this asshole had was always strange. You could feel where he was and how he was feeling. You had decided to ignore it tonight; which clearly had been the wrong choice. You just thought he had still been pissed off over that whole honey incident a couple days ago. Jerk could hold a grudge.

“Yeah?” Came the muffled concerned tone from above.

“Yeah, I mean he called me of all people to help you.” You laughed low. “If anything I would expect to see Asgore here trying to coax you out; not me.”

There was a dry laugh from his side. “Yeah Asgore is a good guy but he can’t help.”

You looked over your shoulder. “But Sans thinks I can?” You dropped your head back letting it hit the door with a soft thud and listened a moment. You could clearly make out Papyrus panting and the flickering and flaring of his orange magic under the door. Was that heat escaping from under his door and that smell? It smelt like him but ten times stronger. Running a hand through your hair you groaned. Damn did you like that smell. “Fuck me.”

He mumbled something that was followed by a heavy rumbling laugh.

“How long are you going to be in there?”

“Don’t know.”

“You hungry?”

“Always.” It sounded almost like he growled the word.

“I can run to Muffet’s.”

“No.”

“Why?”

“Not hungry for that.”

Standing you brush off your butt fixing your short skirt. You stretched slightly and rested a hand on the door. “I’m going to raid the fridge down stairs and find you something. You need to eat, asshole.”

“Fine, bitch.” The halfhearted insult came from behind the door.

Making your way down the stairs you stopped just short of the kitchen to glance up at the closed door. You pulled out your cell phone and dialed Asgore. Maybe you shouldn’t but really you had no clue as to what to do when a monster was sick. Leaning up against the door frame you listen to the phone ring through once…twice…a third time…on the beginning of the fourth you were starting to get nervous when the gravely but kind tone of Asgore answered with a gentle; “Hello?”

“Hey.”

“Oh young one it is so good to hear from you. It has been so long since we have spoken. I know the children miss you as well and…”

“Asgore this isn’t exactly a social call.”

“Oh dear, what seems to be the problem?”

“Papyrus is sick.”

“Sick?” He sounded out right confused.

“Yeah. He’s short of breath. His magic is going out of control. It sounds like his voice is horse. I think he might be running a fever and his insults suck.” You fought back at the lump building in your throat. “Sans called me. I don’t know what to do.”

There was silence for a moment before the kind voice asked with a little glee. “Do you smell anything?”

“Smell?”

“Yes I assume you’ve been near him. Is there a smell?”

“It was through a door but yeah it just smelt well…like him just…just a lot stronger.” You said for a lack of a way to describe it and didn’t really want to tell the father like monster that the smell was intoxicating.

There was a pleasant low chuckle that came across the phone. “Oh young one, Papyrus isn’t sick.”

“He isn’t?”

“No it’s perfectly natural.”

“He’s locked himself in his room for the third day in a row. How is that natural?” You deadpan slightly annoyed. How could Asgore be laughing at a time like this Sans was worried more than normal and Papyrus had locked himself in his room. Truthfully; and you would never tell that bastard but his horse almost broken voice worried you.

“Oh he must just be embarrassed. A heat can do that to a monster.”

“Heat?”

“Yes it means he is ready to mate…”Asgore fell quiet again for a moment but came back with a slight sly to his voice. “Oh but Papyrus doesn’t have a mate does he? That could be troubling.”

“How so?” You ask glancing up at the door to the skeleton’s room.

“Well a heat will last up to a month until a monster has mated.”

“A month?”

“Yes and it can get quite painful if not taken care of.”

You bit you lip rubbing your thighs together. It would take care of two problems at one time or it could be a complete disaster. “Can …” You pause face turning red. Were you really going to ask Asgore about this? Well too late to back out now. “Can it be anyone?” There was a hum of agreement and you nodded. “Thanks Asgore.”

“Good luck young one.”

You chewed on your lip as you disconnected the call. Setting your phone on the counter you raid the fridge like you said you would for a bottle of water and snagged a bottle of honey from the shelf for Papyrus. It would be the excuse to get you in the door before you could talk it out. Maybe if he didn’t just shun you like you expected him too. You scoffed approaching his door. How could he turn it down? It was just sex and you both needed it. Well he needed it you just wanted it. Pressing your ear against door you could hear him panting but it was further away from the door.

“Papyrus open up.” You call knocking on the door nicely.

“No.”

“Come on, I have food.” You said in a sing song voice.

“Don’t fucking care.”

You bristled. “Open the fucking door!” You snapped kicking the door. Why were you even considering helping this jerk, again?

“Fuck Off!”

“Fine!” You throw the food down to the ground and your temper snaps. “Suffer through your heat alone, you prick!”

There was a thud and a scrambling as you stormed and stomped away. The door opened and a flushed Papyrus staggered out. He held onto the door frame to keep his balance. You paused on the steps looking back up at him. His wide eyes sockets locked on you and scanned over your clinging clothing.

“Yeah?” You asked annoyed completely done with his shit today.

“Y…you…you know?”

“Asked Asgore.” His surprise shifted to a glare. “I’m worried about you, alright.” You snapped before he could and ran a hand through your hair. “Asgore says this happens but you need help. I …” You stopped your offer. Fuck Papyrus wouldn’t want you. There were so many female monsters out there and they knew what to do. You? You’re just a dumb human with a short temper. “I wanna help.” You add low.

“W…what?” He stuttered sockets growing impossibly wide. He scans over you again slowly making his way up your legs.

“I can guess you don’t want to go wandering around town in heat. So if you tell me who you want to help I can go get them.” You began to brain storm changing your plan completely missing the drop in his attitude. “Well there is Cinnamon, she likes you…”

“Stop.”

“…or that one that’s always in Muffet’s…” You lick your lips thinking of the next monster not noticing the one creeping upon you.

“Please stop.”

“Oh there is always Metablook.” You add turning quickly. “We could try…”

“Stop listing off monsters like they are pieces of meat!” He snapped grabbing your shoulders pinning you roughly to the wall.

“Hey, I didn’t mean it like that! And these monsters would jump at the chance to fuck you.” You growl out trying to wiggle out of his grasp. The orange flush across his bones spreads as he leaned over you glaring. His chest heaved as he leaned down. You expected him to start yelling directly in the face. Yet his head moved to the side and pressed against your neck through your hair.

“What the fuc….” You stopped and pulled slightly away from him to glare. “Did you just sniff me?”

A low growl rumbled from his chest. “Why do you smell like that?”

“Like what?” You asked confused.

He pushed the hair from your neck and the growl grew louder. “I could smell it through the door but this…” He grumbled low one boney hand tracing over a new bruise on your neck. “You were on a date.”

“Hook up.” You corrected trying to pull out of his grasp.

“He was all over you.” Papyrus stepped up again and his knee pressed between your thighs. You let out a whimper as an orange tongue slipped between his teeth to lick the bruise. “You reek like him.” His knee pressed harder separating your legs and Papyrus stopped his assault for a moment. “You really shouldn’t smell like some strange dude…” His one hand drifted down your body to grasp at your hips. “…or let them this close.” He mumbled nipping at the bruise.

You yipped slightly at the light pain. “You assh…” A moan escaped cutting off your insult when his lower hand had dipped to press against your wet panties. Heat flared across your face. How had that happened already? Papyrus had barely touched you.

“Look at you…” He groaned rubbing you through the thin fabric. “…so ready...” He nipped and pushed his fingers harder against you. “…so willing…” His hand moved up to your waist and you whimpered at the monetary lack of contact. Then he was up against you his hips bucking creating the needed movement. You could feel the bulge in his shorts pressing against you as he dry humped you. “…so fuckable.” His last was words were harsh before he bit your ear.

In a flurry of movement you were turned into the wall face pressed against it. You let out a cry of distress but it morphs into a moan as Papyrus keeps working you with his hand. Tipping your head back in a moan as you twist slightly to see him pulling off his shorts mumbling low curses at his struggle. You fail at fighting back a snicker. Papyrus looks at you a dark playfulness twisting into his smile before he slapped you ass hard. A moaned cry slips out as anticipation wells in you belly.

“Fuck.” He groans as he finally releases himself from the clothing. Your eyes widened and something inside you twists at the glowing orange ethereal member. It was larger than you expected and a small line of orange pre-cum slid down from the tip. “Last ch…chance to…back out.” He groaned grabbing at your panties and skirt pulling them down. “I…once we start I… we’ll have to keep going…” He rubbed his member against your folds; hesitantly leadingly prodding. “You’ll get hurt.” Pain rumbled in his voice. There was no doubt in the words he had spoken. Papyrus knew he would hurt you if you continued down this path. He still hadn’t actually looked at you but you could see he was already ashamed of the thought.

“Pap.” Your voice was gentle something neither of you were used to when it came to the two of you talking. He finally looked up; eye sockets glowing intensely. This was the clam before the storm. Some strange moment you were sharing with a skeleton monster that found you just as annoying as you found him. You nod. “I trust you, Pap.” In a sultry voice you didn’t know you had.

He entered you in one swift movement and you cried out a soundless scream as he seated fully inside. Papyrus groaned into your hair just from feeling the warmth around him. You matched the sound. But then he gripped your hips and started to move, fast. Pulling out and pushing back in so quickly you were seeing stars. Bracing yourself against the wall you cried out each time he hit deep inside you. The sound of bone hitting flesh echoed through the hall mixed with both sets of groans. It was fast and raw and so very needed.

“Pap.” You moan out low as he doubles over on to you licking at your neck. You feel him swell as your walls tighten already around his member.

“Pap I’m going to…”You couldn’t finish he sentence because where Papyrus been licking he bit down hard as he released deep inside of you. The mix of pain and pleasure sent you over the edge and you climaxed with him.

Both fell still for a moment panting he pulled away from you neck and lapped at the blood. You groaned low when he twitched still buried in you folds. He stepped back and withdrew slightly. Another low hiss escaped you lips as he turned you to face him. He was at you neck sharp teeth drifting back and forth between deciding wither to bite again. Papyrus made slow thrusts forward just ever so slightly moving inside of you. He arched over you forcing you on to your toes.

“Let me help.” He purred.

Papyrus maneuvered your body till you were in a better position. Your legs were off the ground balancing on his hip bones with you back snug against the wall. A half smile grew on your face seeing his orange blush and disheveled look all the while he kept up those tantalizing shallow thrusts. He closed his eyes an orange glow slightly escaping from them.

“Pap.” You say once as he bucked hard into you out of his rhythm. He opened his eyes to look at you. Your chest heaved still restrained by your shirt and bra. The tall skeleton grumbled to himself.

“Can you take that shit off.” He growled tugging at your shirt. You give a sly grin ready to make a snarky remake before he added. “Or I can rip it off.” You squeaked and unbuttoned the blouse. You liked this blouse. He watched your fingers move deftly across the buttons. Slinking the shirt off your shoulders you twist your arms behind you and unclasp your bra. The moment your chest is bare Papyrus has a hand running up your stomach.

He takes his time exploring; touching your flesh in different spots. His hand drifted to one breast. He squeezed it and ran his thumb over the nipple. You hissed sharply and he froze looking at you. You nod and he continues is exploration. Opening your eyes you can see there is a difference in him. Before there was a wild look but currently he subdued and just curious. The harsh glow of his magic and softened to a light back glow. He had burned off some of the wild heat magic that much you had been sure. You began to let your mind wander thinking over the idea of a monster’s heat. You cry out and look back to see Papyrus glaring at you his teeth tight around your one nipple.

“Don’t think of anything but me.” He grumbled before licking the nub of flesh. He pulls almost completely out of you stopping the constant shallow movement. You felt empty.

“Fuck me.” The words tumbled out of your mouth as you gripped at you sweat slicked hair trying to breathe.

He chuckled low and shoved back into you hard. You squeaked and shivered lurching forward to wrap your arms around his neck. “I plan to.” He growls menacingly gripping your ass and lifting you off him just to slam back in with a wicked chuckle. You let out a moan knowing it was going to be a long night.

**~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~**

You had to stop yourself from stretching the next morning as you awoke. Every part of you ached but in that happy satisfied way. You groaned low trying to sit up. Gods did your lower half hurt. The tingling in your legs hadn’t even subsided yet. Rubbing at the crook of your neck you feel something dried there. You scratched at it and winced. Pulling you hand away to set the red flecks on your fingers with a glare.

“Fuck me.” You hiss low.

Fingers wrapped carefully around your waist tugging you back. “Did that last night.” The lazy words were spoken pressed into your hip by a lazy skeleton.

“Asshole.” You slapped at his hand slightly. “You bit me.”

“Yep.” He answered sitting up enough to reach for his pack of cigarettes. Placing one in his mouth, he took a match from the box beside it and struck the chemical head against the side and sulfur filled your nose. Papyrus rolled to his side putting out the match before drawing in a breath from the cigarette. You watch him take a few more drags before snatching the thing from him. He doesn’t even glare just runs a few light touches up your back tracing over a few tender spots.

You puffed at the filtered cigarette wincing when he brushed something that would be bruised for a few days. Why had you ever given these things up? Papyrus sat up positioning himself behind you and rested his head on top of yours before taking back his smoke. You whine at the loss of the old familiar burn. He swoops down and kisses your bite make before kissing your temple. Leaning back into him he wraps an arm around your waist holding you tight against him. There was a comfortable silence before he spoke.

He buried his face in your messy hair saying. “You’re still a bitch.”

A smile cracked across you face and you started to laugh. “Fuck off, asshole.”

You felt his smile widen against your back.

**Author's Note:**

> Hey guys! Um sorry if this was kinda crappy. I suck at smut. I was bored and this is what comes out of that boredom. Kudos and comments welcomed!


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